JP2588655B2 - Circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly to a circuit breaker having improved performance of an arc extinguishing device.

[0002]

2. Description of the Related Art As a conventional circuit breaker of this type, for example, a circuit breaker described in Japanese Patent Application Laid-Open No. 62-163235 is known. Therefore, the circuit breaker described in this publication will be described with reference to FIGS. In FIG. 18, reference numeral 1 denotes a movable contact, 2 denotes a movable contact fixed to one end of the movable contact 1, 3 denotes a fixed contact to which the movable contact 2 comes and goes when the movable contact 1 rotates, and 4 denotes a linear conductor. A connection conductor comprising a portion 4A and a U-shaped conductor portion 4B to form a blowout coil, 5A is a terminal portion electrically connected to the connection conductor 4 by a screw 6, and 5B is a terminal paired with the terminal portion 5A. A fixed contact 3 comprising a fixed contact 3 and a connecting conductor 4; an arc extinguishing grid 8; a mechanism 9 for opening and closing the movable contact 1; a detecting unit 10 for detecting an abnormal current; , 12 are containers for storing the above members.

Next, the operation will be described. At the time of energization shown in FIG. 19A, the movable contact 2 and the fixed contact 3 are in a closed state in contact with each other, and the terminal 5A, the connection conductor 4, the fixed contact 3, the movable contact 2, the shunt 11, and the terminal 5B are connected. A current flows through the path as shown by arrow I. Then
When the mechanism section 9 is manually operated or the detection section 10 detects an abnormal current and sends an operation signal, the mechanism section 9 operates to open the contacts 2 and 3. However, when the abnormal current is a short-circuit current, the movable contact 1 is repelled by the electromagnetic repulsive force prior to the operation of the mechanism unit 9 and the contacts 2 and 3 are opened. With the opening of each contact 2,3, these contacts 2,3
An arc A is generated between the contacts, and the distance between the contacts 2 and 3 is changed to the arc A.
19B, the arc A is driven in the direction of the arc-extinguishing grid 8 by the influence of the magnetic field of the blow-out coil forming the connection conductor 4 as shown in FIG. Extend A. At this time, since the blowout coil is located near each of the contacts 2 and 3 at the time of closing, the magnetic field generated by the blowout coil is intensively applied to the arc A immediately after the arc is fired, and the arc A is rapidly driven. , And the arc A voltage rises sharply to limit the current. Further, when the distance between the contacts 2 and 3 increases, FIG.
Since the movable contact 1 is located above the upper current path of the blowout coil as shown in (c), the action of driving and extending the arc A by the magnetic field generated by the blowout coil is substantially eliminated. The arc A is driven and extended toward the arc-extinguishing grid 8 by the action of the arc-extinguishing grid 8 and the action of the current path in the arc-extinguishing chamber space including the arc A, and is cooled by the arc-extinguishing grid 8 to interrupt the current.

[0004]

However, in the conventional circuit breaker, since the connection conductor 4 forming the blowout coil is disposed near the movable contact 2 and the fixed contact 3 when the circuit breaker is closed, the circuit breaker is not operated. Although a magnetic field for driving and extending the arc A immediately after the arc can be applied intensively, most parts other than the movable contact 2 of the movable contact 1 are located outside the blowout coil at the time of closing. As a result, a magnetic field component for driving the movable contact 1 in the direction in which the movable contact 1 is separated is scarcely obtained. However, there is a problem that the distance between the contacts 2 and 3 is slowed down, and sufficient current limiting performance cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve the rotation speed of a movable contact at the initial stage of opening and to increase the driving force for extending an arc toward a terminal. It is an object of the present invention to provide a circuit breaker having excellent current limiting performance.

[0006]

According to a first aspect of the present invention, there is provided a circuit breaker having a center of rotation, a movable contact fixed to one end of the movable contact, and the movable contact being rotated by the movable contact. A fixed contact that is fixed to the distal end and is elastically supported so as to be rotatable around the base end, and is positioned parallel and below the movable contactor when closed. A conductor, a connection conductor having a conductor at one end and the other end connected to the terminal, and forming a blowout coil for generating a magnetic field for driving an arc generated between the contacts to extend toward the terminal; When the direction in which the movable contact is separated from the fixed contact by rotating the movable contact from the closed state is set to be upward, the current path and the terminal portion above the blowout coil are closed. The above movable contact and fixed contact Respectively positioned above the position of the contact surface, when opened it is one that is configured to be positioned respectively below the position of the surface of the movable contact of the movable contactor.

A circuit breaker according to a second aspect of the present invention has a movable contact having a center of rotation and having a movable contact fixed at one end, and is movable toward and away from the movable contact by rotating the movable contact. A fixed contact, a fixed contact is fixed to the distal end, and is elastically supported to be rotatable about the base end side, and a conductor portion positioned parallel and below the movable contact at the time of closing,
A connection conductor having a conductor portion at one end and the other end connected to the terminal portion and forming a blowout coil for generating a magnetic field for driving an arc generated between the contacts to extend toward the terminal portion; When the direction in which the movable contact is separated from the fixed contact by the rotation of the movable contact from the formed state is set to be upward, the current path and the terminal portion above the blowout coil are closed when the movable contact is closed. It is configured to be located above each other and to be located below the movable contact at the time of opening.

A circuit breaker according to a third aspect of the present invention has a movable contact having a center of rotation and having a movable contact fixed at one end, and is movable toward and away from the movable contact by rotating the movable contact. A fixed contact, a fixed contact is fixed to the distal end, and is elastically supported to be rotatable about the base end side, and a conductor portion positioned parallel and below the movable contact at the time of closing,
A connection conductor having a conductor portion at one end and the other end connected to the terminal portion and forming a blowout coil for generating a magnetic field for driving an arc generated between the contacts to extend toward the terminal portion; When the direction in which the movable contact is separated from the fixed contact by the rotation of the movable contact from the established state is set to be upward, the blowout coil is at least located closer to the rotation center side than the fixed contact when closed. And forming two sides substantially parallel to the movable contact, one of the two sides is located below the movable contact, and the other side is located above the movable contact, respectively.
At the time of opening, the two sides are respectively located below the movable contact.

The circuit breaker according to a fourth aspect of the present invention is the circuit breaker according to the first to third aspects, wherein the conductor has a substantially L-shape and forms a part of the blowout coil. And the center of rotation of the movable contact is located above the contact surface of each contact when closed.

[0010]

According to the first aspect of the invention, at the initial stage of the separation of the movable contact from the fixed contact, a magnetic field component for driving the movable contact in the separation direction is formed intensively, and the movable contact is opened from the fixed contact. The separation speed of the movable contact immediately after separation increases,
In addition, the conductor to which the fixed contact is fixed is rotated in the direction opposite to the movable contact by the action of the magnetic field generated by the blowout coil and the repulsion of the movable contact. Quickly reach the minimum inter-contact distance,
The arc is driven and extended at an early point by the magnetic field of the blowout coil to improve the current limiting performance of the circuit breaker.

Further, according to the second aspect, a magnetic field component for driving the movable contact in the separating direction is formed intensively at the initial stage of separating the movable contact from the fixed contact, and the movable contact is opened from the fixed contact. Immediately after separation, the opening speed of the movable contact increases, and the conductor to which the fixed contact is fixed rotates in the opposite direction to the movable contact due to the action of the magnetic field by the blowout coil and the repulsion of the movable contact. And then after separation,
The minimum distance between the contacts required to drive the arc is quickly reached, and the arc is driven and extended at an earlier point in time by the magnetic field of the blowout coil and the terminal portion, thereby improving the current limiting performance of the circuit breaker.

According to the third aspect of the invention, at the initial stage of the separation of the movable contact from the fixed contact, a magnetic field component for driving the movable contact in the separation direction is formed intensively, and the movable contact is opened from the fixed contact. Immediately after separation, the opening speed of the movable contact increases, and the conductor to which the fixed contact is fixed rotates in the opposite direction to the movable contact due to the action of the magnetic field by the blowout coil and the repulsion of the movable contact. And then after separation,
The minimum distance between the contacts required to drive the arc is quickly reached, and the arc is driven and extended only by the magnetic field of the blowout coil to improve the current limiting performance of the circuit breaker.

According to the fourth aspect of the present invention, at the initial stage of the separation of the movable contact from the fixed contact, a magnetic field component which attracts the conductor portion by the current flowing through the movable contact and drives the movable contact in the separation direction is generated. The moving contact is formed intensively, and the moving speed of the moving contact immediately after the moving contact is separated from the fixed contact increases. Rotate in the opposite direction to the movable contact by the repulsion of the contact, and after opening, quickly reach the minimum inter-contact distance required to drive the arc, and the arc is moved earlier by the magnetic field of the blowout coil Drive and extend to improve the current limiting performance of the circuit breaker.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG.

First, the circuit breaker of the first invention will be described. FIG. 1 is a cross-sectional view showing a main part of an embodiment of the circuit breaker of the first invention, showing a closed state where a movable contact and a fixed contact are in contact with each other, and FIG. 1 showing a state in which a movable contact and a fixed contact in the circuit breaker shown in FIG. 1 are opened. FIG. 3 shows a movable contact and a fixed contact of a circuit breaker according to another embodiment of the first invention. FIG.

As shown in FIGS. 1 and 2, the circuit breaker according to one embodiment of the first invention mainly differs in the structure of portions corresponding to the movable contact 1 and the fixed contact 7. It is configured according to a conventional circuit breaker. That is, the movable contact 1 is formed of a linear conductor piece having the movable contact 2 fixed to the distal end, and the base end thereof is elastically supported via the shunt 14 by the conductor 13 fixed to the bottom of the container 12. And a rotation center 15 at the base end. Below the movable contact 1, there is provided a linear conductor (repulsive conductor) 4A having a fixed contact 3 which can be brought into contact with and separated from the movable contact 2 fixed to the tip. This repulsion conductor 4A has a shunt 16 at its base end.
In the closed state in which the fixed contact 3 is in contact with the movable contact 2, the movable contact 1 is parallel to the movable contact 1 while being elastically supported at one end of a connection conductor 4 described later and having a rotation center 17 at the base end. And located below. The fixed contact 3 and the repulsive conductor 4A constitute a repulsor. The connection conductor 4 has one end connected to the repulsion conductor 4A and the other end connected to the terminal portion 5A by the screw 6 as described above, and has an arc generated between the movable contact 2 and the fixed contact 3. A blow-out coil for generating a magnetic field for driving the extension toward the terminal portion 5A is formed. And the fixed conductor is comprised by the connection conductor 4 and the terminal part 5A.

When the circuit breaker having the above structure is energized, the terminal 5A, the shunt 16, the connection conductor 4, the repulsion conductor 4A, the fixed contact 3, the movable contact 2, the shunt 14,
A current flows through the path of the conductor 13 and another terminal (see FIG. 18). When the opening operation of the movable contact 1 and the repulsor (consisting of the fixed contact 3 and the repulsive conductor 4A) is started from the energized state by the action of an electromagnetic repulsive force or a mechanism (corresponding to the numeral 9 in FIG. 18), the movable contact 1 is moved. The contact 2 is separated from the fixed contact 3 to generate an arc.

In this operation, when the direction in which the movable contact 2 opens from the fixed contact 3 by rotating the movable contact 1 from the closed state is upward, the movable contact 1 is the connection conductor 4. Due to the action of the magnetic field generated in the blowout coil, in particular, the attraction force with the current path above the blowout coil and the repulsion force with the repulsion conductor 4A, respectively, causes rapid rotation around the rotation center 15. Simultaneously with this operation, the repulsive element acts on the action of the magnetic field generated in the blowout coil, in particular, the attractive force with the current path below the blowout coil which is close below the repulsive conductor 4A and the repulsion with the movable contact 1 Each of the repulsive forces rapidly rotates downward about the rotation center 17. In this way, the distance between the contacts in the initial stage of opening increases rapidly, and the distance between the contacts quickly reaches the minimum value required for driving the arc.
In addition, since the current path above the blowout coil is located close to the arc immediately after the opening, the arc is effectively driven and extended in the direction of the arc-extinguishing grid 8 by the magnetic field of the blowout coil. Then, the arc voltage rises sharply and the current is effectively limited.

Further, when the distance between the contacts increases, as shown in FIG. 2, the movable contact 1 is located above the current path above the blowout coil, so that the arc driven by the magnetic field generated in the blowout coil is driven. The arc is substantially eliminated, but the arc is driven and extended toward the arc-extinguishing grid 8 by the operation of the arc-extinguishing grid 8 and the current path in the arc-extinguishing space including the arc. Is shut off.

Although the connection conductor 4 of the circuit breaker of the above embodiment has been described as being formed as a blow-out coil of one or more turns, the connection conductor in the present invention is, as shown in FIG. It may be formed as a blowout coil of less than. In this case, the repulsive element including the repulsive conductor 4A and the fixed contact 3 forms a current path below the blowout coil. In such a circuit breaker to which the connection conductor 4 is applied, the repulsor does not drive rapidly as in the case of the above embodiment, and the connection conductor 4 is provided with a slit 4C to open and close the movable contact 1. However, the fixed conductor composed of the connection conductor 4 and the terminal portion 5A can be easily formed by bending a single conductive material, and the repulsor can be easily assembled. Therefore, the manufacturing cost of the device can be reduced.

Next, the circuit breaker of the second invention is shown in FIGS.
Explanation will be given based on FIG. In each of the drawings, FIG. 4 is a view corresponding to FIG. 1 showing an essential part of an embodiment of the circuit breaker according to the second invention, and FIG. 5 is a circuit breaker shown in FIG. FIG. 6 is a diagram corresponding to FIG. 1, showing a state in which the movable contact and the fixed contact of a circuit breaker according to another embodiment of the second invention are shown.

As shown in FIGS. 4 and 5, the circuit breaker of this embodiment has the same configuration as the circuit breakers shown in FIGS. 1 and 2 except for the connection conductor 4. That is, the circuit breaker of the present embodiment has the center of rotation 14 and the movable contact 1 having one end to which the movable contact 2 is fixed. The fixed contact 3 is fixed to the distal end and is elastically supported so as to be rotatable around a rotation center 17 at the base end, and is parallel and downward with respect to the movable contact 1 when closed. A blowout that has a repulsive conductor 4A located therein and a repulsive conductor 4A at one end and the other end is connected to the terminal 5A and generates a magnetic field for driving an arc generated between the contacts 2 and 3 to extend toward the terminal 5A. And a connection conductor 4 forming a coil.

When the direction in which the movable contact 2 is separated from the fixed contact 3 by the rotation of the movable contact 1 from the closed state is upward, the blowout coil forming the connection conductor 4 As shown in FIGS. 4 and 5, each of the upper current path and the terminal portion 5A is formed as a straight, coplanar surface, and is located above the movable contact 1 when closed.
At the time of opening, it is configured to be located below the movable contact 1 respectively.

Therefore, when the circuit breaker having the above configuration is energized, similarly to the circuit breakers shown in FIGS. 1 and 2, the terminal portion 5A, the shunt 16, the connection conductor 4, the repulsion conductor 4A, the fixed contact 3, the movable contact 3, A current flows through the path of the contact 2, the shunt 14, the conductor 13, and another terminal (see FIG. 18), and the electromagnetic repulsive force or the action of the mechanism (corresponding to the numeral 9 in FIG. 18) from the energized state. When the opening operation of the movable contact 1 and the repulsor (consisting of the fixed contact 3 and the repulsive conductor 4A) is started, the movable contact 2 is separated from the fixed contact 3 and an arc is generated.

In this operation, since the movable contact 1 has its tip end located in the blowout coil which is the connection conductor 4, the action of the magnetic field generated in the blowout coil
In particular, the current path and terminal 5 above the blowout coil
The movable contact 1 is rapidly rotated upward about the rotation center 15 by the attraction force with A and the repulsion force with the repulsion conductor 4A. Simultaneously with this operation, the repellent element acts on the action of the magnetic field generated in the blow-out coil, in particular,
A lower portion of the blow-out coil is rapidly rotated around the rotation center 17 by an attractive force with a current path below the blow-out coil and a repulsive force with the movable contact 1. Thus, the distance between the contacts in the initial stage of opening rapidly increases, and the distance between the contacts quickly reaches the minimum value necessary for driving the arc, and the influence of the blowout coil and the magnetic field of the terminal portion 5A. Then, the arc is driven and extended in the direction of the arc-extinguishing grid 8, so that the arc voltage sharply rises immediately after the opening and the current is effectively limited. After that, it functions similarly to the circuit breaker shown in FIGS.

Although the connection conductor 4 of the circuit breaker of the above embodiment has been described as being formed as a blow-out coil having one or more turns, the connection conductor in the present invention is, as shown in FIG. It may be formed as a blowout coil of less than. The connection conductor 4 shown in FIG. 6 is similar to the one shown in FIG.
Is provided with a slit 4C in a portion where the light beam passes. This connection conductor 4 can also achieve the same operation and effect as those shown in FIG.

Next, the circuit breaker of the third invention is shown in FIGS.
A description will be given based on FIG. In each of the drawings, FIG. 7 is a diagram corresponding to FIG. 1 showing a main part of an embodiment of the circuit breaker of the third invention,
FIG. 8 is a view corresponding to FIG. 1 showing a state in which a movable contact and a fixed contact in the circuit breaker shown in FIG. 7 are opened, and FIGS. 9 to 11 show movable states of the circuit breaker according to another embodiment of the third invention. FIG. 4 is a diagram corresponding to FIG. 3 showing a contact and a fixed contact.

As shown in FIGS. 4 and 5, the circuit breaker of the present embodiment includes the same movable contact 1 and repulsive conductor 4A as the circuit breakers shown in FIGS. Also,
The connection conductor 4 in the present embodiment has a repulsion conductor 4A at one end and the other end is connected to the terminal 5A, and generates a magnetic field for driving an arc generated between the movable contact 2 and the fixed contact 3 to extend toward the terminal 5A. The configuration of the blowout coil to be generated is the same as in the above embodiments.

When the blowout coil is closed, the blowout coil forms two upper and lower sides that are substantially parallel to the movable contact 1, and most of the two parallel sides are closer to the rotation center 14 than the fixed contact 3. Is formed. One of the two sides is located below the movable contact 1, and the other side is located above the movable contact 1. However, at the time of opening, the two sides are both configured to be located below the movable contact 1. The terminal portion 5A of the connection conductor 4 is bent so as to be located below one side above the blowout coil.

Therefore, when the circuit breaker having the above configuration is energized, the terminal portion 5A, the shunt 16, the connection conductor 4, and the repulsion conductor 4A are energized as in the circuit breakers shown in FIGS. 1, 2, 4 and 5. , Fixed contact 3, movable contact 2, shunt 14,
A current flows through the path of the conductor 13 and another terminal portion (see FIG. 18). When the opening operation of the repellent element (consisting of the fixed contact 3 and the repulsive conductor 4A) is started, the movable contact 2 is separated from the fixed contact 3 and an arc is generated.

In this operation, the movable contact 1 operates in the same manner as the circuit breaker shown in FIGS. 4 and 5 because the tip end of the movable contact 1 is located in the blowout coil which is the connection conductor 4. In the example, after the distance between the movable contact 2 and the fixed contact 3 reaches the minimum value for driving the arc, the arc is not affected by the magnetic field of the terminal portion 5A, but is affected by the magnetic field of only the blowout coil. Then, it is driven and extended in the direction of the arc-extinguishing grid 8.

Although the connection conductor 4 of the circuit breaker of the above embodiment has been described as being formed as a blow-out coil having one or more turns, the connection conductor according to the present invention is, as shown in FIGS. Alternatively, it may be formed as a blowout coil having less than one turn. That is, the connection conductor 4 shown in FIG. 9 is provided with the slit 4C only in a portion that passes when the movable contact 1 is driven to open and close. Further, in addition to the slit 4C, the connection conductor 4 shown in FIG. 10 may be provided with an exhaust slit 4D for exhausting a gas generated by the generation of an arc in a vertical portion continuous with the terminal portion 5A. As in the connection conductor 4 shown in FIG. 11, a slit 4E in which the two slits 4C and 4D are continuous may be provided. These connecting conductors 4 are also shown in FIG.
The same operation and effect as those shown in FIG. 7 can be expected.

Further, the circuit breaker of the fourth invention is shown in FIGS.
This will be described with reference to FIG. In each of the drawings, FIG. 12 is a view showing a main part of an embodiment of the circuit breaker according to the third invention. FIG. 13 is an equivalent view of FIG. 1 showing an open state, and FIG. 13 is an open state of the circuit breaker shown in FIG. FIG. 14 is a diagram showing a main part of another embodiment of the circuit breaker according to the third invention, and FIG. 14 is a diagram corresponding to FIG. 1 showing an open state, and FIG. 15 is a circuit breaker shown in FIG. 2 corresponding to FIG. 2 showing the open state of the circuit breaker, FIG. 16 is a view showing the main part of still another embodiment of the circuit breaker of the third invention, FIG. FIG. 3 is a diagram corresponding to FIG. 2 showing an open state of the circuit breaker shown in FIG.

The circuit breaker of the embodiment shown in FIGS. 12 and 13 is provided with the same movable contact 1 as the circuit breaker shown in FIGS. However, as shown in each drawing, the repulsion conductor 4A in the present embodiment has a base connected to one end of the connection conductor 4 having a linear shape in the horizontal direction, and has a rotation center 17 at the base. . The repulsion conductor 4A includes a vertical portion 4F extending downward from the rotation center 17 to the connection conductor 4 in the closed state, and a horizontal portion 4G bent at 90 ° from the vertical portion 4F and extended toward the terminal portion 5A. Are formed in an L-shape. The repulsion conductor 4A and the connection conductor 4 form a part of a blowout coil, and the center of rotation 17 is located above the contact surface of the movable contact 2 and the fixed contact 3 when closed. Have been. Therefore, the repulsive conductor 4
The current path and terminal portion 5A above the blowout coil formed by A and the connection conductor 4 are located above the positions of the contact surfaces of the movable contact 2 and the fixed contact 3 when closed, respectively.
At the time of opening, they are located below the position of the surface of the movable contact 2 of the movable contact 1.

In the circuit breakers of the embodiments shown in FIGS. 14 and 15, as shown in the figures, the linear connection conductor 4 formed in the same manner as in the above-mentioned embodiment has a movable contactor when closed. 1
It is configured so as to be located above the movable contact and to be located below the movable contact at the time of opening. An L-shaped repulsion conductor 4A having a vertical portion 4F formed longer than that of the above-described embodiment is rotatably connected to one end of the connection conductor 4. When the fixed contact 3 contacts the movable contact 2, the movable contact 1 is configured to be parallel to the connection conductor 4 when the contact is closed. Therefore, the repulsive conductor 4
The current path and the terminal portion 5A on the upper part of the blowout coil formed by A and the connection conductor 4 are respectively located above the movable contact 1 when closed, and are respectively located below the movable contact 1 when opened. I have.

In the circuit breakers of the embodiments shown in FIGS. 16 and 17, as shown in the drawings, the connecting conductors 4 extend vertically from the upper and lower ends of the vertical portion in the horizontal direction. And a terminal portion 5A, and a resilient conductor 4 formed in an L-shape at an extended end of the horizontal portion located above the terminal portion 5A.
A is rotatably connected as in the above embodiments. Then, when the fixed contact 3 comes into contact with the movable contact 2,
The movable contact 1 is configured to be parallel to the connection conductor 4. Therefore, the repulsion conductor 4A and the connection conductor 4
When closed, the horizontal portion of the connection conductor 4 and the horizontal portion of the repulsion conductor 4A are substantially parallel to the movable contact 1 when the blowout coil is closed, and most of both horizontal portions are fixed contact 3 It is located closer to the rotation center 14. At this time, the horizontal portion of the repulsion conductor 4A is located below the movable contact 1, and the horizontal portion of the connection conductor 4 is located above the movable contact 1. However, at the time of opening, both the horizontal parts are configured to be located below the movable contact 1.

Accordingly, in the circuit breakers shown in FIGS. 12 to 17, the vertical portion 4F of the repulsive conductor 4A acts on the repulsive conductor 4A by the current flowing through the movable contact 1, so that the repulsor (the fixed contact and the repulsive conductor 4A) are applied. ) In the opening direction is increased, and the distance between the contacts 2 and 3 in the initial stage of opening can be increased more rapidly. In the maximum opening position for a long time.

[0038]

As described above, according to the first aspect, when the direction in which the movable contact is opened from the fixed contact by the rotation of the movable contact from the closed state is upward,
The upper current path and the terminal portion of the blowout coil are respectively located above the positions of the contact surfaces of the movable contact and the fixed contact when closed, and are located above the position of the movable contact surface of the movable contact when opened. A circuit breaker having excellent current limiting performance that can be positioned at the lower side to improve the rotation speed of the movable contact at the initial stage of opening and to increase the driving force for extending the arc toward the terminal. Can be provided.

According to the second aspect of the present invention, when the direction in which the movable contact separates from the fixed contact by rotating the movable contact from the closed state is upward, the current in the upper part of the blowout coil is increased. The path and the terminal portion are respectively located above the movable contact at the time of closing, and are respectively located below the movable contact at the time of opening, thereby improving the rotational speed of the movable contact at the initial stage of opening. At the same time, it is possible to provide a circuit breaker having an excellent current limiting performance capable of increasing the driving force for extending the arc toward the terminal.

According to the third invention, when the direction in which the movable contact is separated from the fixed contact by rotating the movable contact from the closed state is upward, the blowout coil is closed. Sometimes, at least two sides are located on the rotation center side of the fixed contact and substantially parallel to the movable contact, one of the two sides is located below the movable contact, and the other side is By being located above the movable contact, and at the time of opening, the two sides are respectively located below the movable contact, thereby improving the rotation speed of the movable contact at the initial stage of the opening and improving the terminal of the arc. It is possible to provide a circuit breaker having an excellent current limiting performance capable of increasing the extension driving force to the side.

According to the fourth invention, the conductor in the first to third inventions has a substantially L-shape and forms a part of the blowout coil, and the center of rotation of the conductor is closed. By positioning the movable contact above the contact surface between the fixed contact and the movable contact at the time of opening, the rotating speed of the movable contact at the initial stage of opening is improved, and the driving force for extending the arc toward the terminal portion is increased. Thus, a circuit breaker having excellent current limiting performance can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of a circuit breaker of the first invention, showing a closed state in which a movable contact and a fixed contact are in contact with each other.

FIG. 2 is a sectional view showing a state where a movable contact and a fixed contact in the circuit breaker of FIG. 1 are opened.

FIG. 3 is a perspective view showing a movable contact and a fixed contact of a circuit breaker according to another embodiment of the first invention.

FIG. 4 shows an embodiment of the circuit breaker of the second invention.
FIG.

FIG. 5 is a sectional view corresponding to FIG. 2, showing the circuit breaker of FIG. 4;

FIG. 6 is a perspective view corresponding to FIG. 3 showing a circuit breaker according to another embodiment of the second invention.

FIG. 7 shows an embodiment of the circuit breaker of the third invention.
FIG.

FIG. 8 is a sectional view corresponding to FIG. 2 showing the circuit breaker of FIG. 7;

FIG. 9 is a perspective view corresponding to FIG. 3, showing a circuit breaker according to another embodiment of the third invention.

FIG. 10 is a perspective view, corresponding to FIG. 3, showing a circuit breaker according to still another embodiment of the third invention.

FIG. 11 is a perspective view corresponding to FIG. 3 showing a circuit breaker according to still another embodiment of the third invention.

FIG. 12 is a cross-sectional view corresponding to FIG. 1 showing one embodiment of the circuit breaker of the fourth invention.

FIG. 13 is a sectional view corresponding to FIG. 2 showing the circuit breaker of FIG. 12;

FIG. 14 is a perspective view corresponding to FIG. 1 showing a circuit breaker according to another embodiment of the fourth invention.

FIG. 15 is a sectional view corresponding to FIG. 2, showing the circuit breaker of FIG. 14;

FIG. 16 is a perspective view corresponding to FIG. 1 showing a circuit breaker according to still another embodiment of the fourth invention.

FIG. 17 is a sectional view corresponding to FIG. 2 showing the circuit breaker of FIG. 16;

FIG. 18 is an overall sectional view showing an example of a conventional circuit breaker.

19A and 19B are cross-sectional views illustrating the opening operation of the movable contact of the circuit breaker in FIG. 18, and FIG. 19A illustrates a current flow in a closed state where the movable contact of the movable contact contacts the fixed contact. Figure,
(B) is a figure which shows the behavior of the arc immediately after opening, (c) is a figure which shows the state in which an arc extinguishing grid drives an arc.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Movable contact 2 Movable contact 3 Fixed contact 4 Connection conductor which forms a blowout coil 5A Terminal part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Fukuya 1-8 Midoricho, Fukuyama City, Hiroshima Prefecture Mitsubishi Electric Corporation Fukuyama Works (72) Inventor Shiro Murata 1-8 Midoricho Fukuyama City, Hiroshima Prefecture Mitsubishi Electric Corporation (56) References JP-A-1-206522 (JP, A) JP-A 5-6644 (JP, U) JP-A-6-4036 (JP, U) JP-A 62-152341 ( JP, U)

Claims (4)

(57) [Claims] A movable contact having a center of rotation and having a movable contact fixed at one end; a fixed contact which can be brought into contact with and separated from the movable contact by the rotation of the movable contact; A conductor portion which is fixed and elastically supported so as to be rotatable around the base end side and which is positioned parallel to and below the movable contact at the time of closing, and having a conductor portion at one end and the other end A connection conductor that is connected to the terminal portion and forms a blowout coil that generates a magnetic field that drives the arc generated between the contacts to extend toward the terminal portion, and the movable contact rotates from the closed state. As a result, when the direction in which the movable contact separates from the fixed contact is set to be upward, the current path above the blowout coil and the terminal portion are above the position of the contact surface of the movable contact and the fixed contact when closed. Located and open A circuit breaker which is located below a position of a surface of a movable contact of the movable contact when formed. 2. A movable contact having a center of rotation and having a movable contact fixed at one end, a fixed contact that can be brought into contact with and separated from the movable contact by rotation of the movable contact, and a fixed contact provided at a tip end. A conductor portion which is fixed and elastically supported so as to be rotatable around the base end side and which is positioned parallel to and below the movable contact at the time of closing, and having a conductor portion at one end and the other end A connection conductor that is connected to the terminal portion and forms a blowout coil that generates a magnetic field that drives the arc generated between the contacts to extend toward the terminal portion, and the movable contact rotates from the closed state. When the direction in which the movable contact separates from the fixed contact is set to be upward, the current path and the terminal portion above the blowout coil are respectively located above the movable contact when closed, and when opened, the Movable contact Circuit breakers, each of which is located below the circuit breaker. 3. A movable contact having a center of rotation and having a movable contact fixed to one end, a fixed contact that can be brought into contact with and separated from the movable contact by rotation of the movable contact, and a fixed contact provided at a tip end. A conductor portion which is fixed and elastically supported so as to be rotatable around the base end side and which is positioned parallel to and below the movable contact at the time of closing, and having a conductor portion at one end and the other end A connection conductor that is connected to the terminal portion and forms a blowout coil that generates a magnetic field that drives the arc generated between the contacts to extend toward the terminal portion, and the movable contact rotates from the closed state. Accordingly, when the direction in which the movable contact is separated from the fixed contact is set to be upward, the blowout coil is at least located closer to the rotation center than the fixed contact and substantially parallel to the movable contact when closed. Form two sides And one side of the two sides is located below the movable contact and the other side is located above the movable contact, respectively, and when opened, the two sides are located below the movable contact, respectively. Features a circuit breaker. 4. The conductor portion has a substantially L-shape and forms a part of the blowout coil, and the center of rotation of the conductor portion is located above a contact surface of each contact when the conductor is closed. The circuit breaker according to any one of claims 1 to 3, wherein: